Elastic beaeing fob



,TES

ELASTIG BEARING FOR RAILROAD-CHAIRS.

Specification of Letters Patent No. 15,036, dated June 3, 1856.

To all whom t may concern.'

Be it known that I, D. L. Davis, of Dedham, in the county of Norfolk andState of h/Iassachusetts, have invented a new and Improved Method ofApplying Elastic Bearings Beneath Railroads, Rails, Frogs, Switches,&c., of which the following is a full, clear, and exact description,reference being had to the annexed drawings, making part of thisspecification, in which- Figure l, is a plan of a chair having myimprovements attached; Fig. 2, a section upon the line A, A, Fig. l;Fig. 3, a section upon the line B, B, Fig. 1.

The effort has frequently been made to diminish the rigidity of thesubstructure of rail roads, and the injurious effects of this rigidityupon the rolling stock, by the introduction of india. rubber or someother elastic substance between the substructure and the rail. Allefforts to accomplish this, have however signally failed on account ofthe difficulty experienced in preserving the elastic material made useof, from speedy destruction, and no means have heretofore been devisedof effecting this end. Then the india rubber' has been placed beneaththe rail and between it and the chair, it has invariably been rapidlydestroyed by the concussions and frictions to which it was exposed, theindia rubber being worn up into threads which are forced out frombeneath the rail. Where the elastic material has been put beneath thechair and between it and the sleeper the same destructive process wenton though not quite so rapidly as in the former case.

'Io remove the above difficulty and to enable me to interpose an elasticsubstance between the substructure and the rail is the object of mypresentinvention, which consists in the use of a flanged metallic platewhich is placed over the india rubber or other elastic substance for thepurpose of relieving it from the wear and friction which has heretoforeproved so destruct-ive to it the protecting plate or shield being leftentirely free to vibrate in a vertical direction independent of thespikes which confine the chair to the sleeper, while it is prevented byflanges or other similar means from moving horizontally, by which meansthe india rubber is protected from the abrasion which has heretofore sospeedily destroyed it.

To enable others skilled in the art to understand my invention I willproceed to describe the manner in which I have carried it out.

IIn the accompanying drawings C, is a chair of the usual constructionupon which is placed a disk or plate of india rubber D, which is madeslightly smaller than the space between the sides of the chair which isto receive it; thus the disk is covered by an iron plate E, so formedand applied to the chair as to be incapable of any motion except in avertical direction, it being closely fitted between the sides of thechair as seen in Fig. 2, while the flanges F, effectually prevent anymotion in a longitudinal direction and in order that it may have freeroom to play up and down, it is essential that it be entirelyuncontrolled by the spikes which confine the chair to the rail.

It is well known that the substructure of rail roads cannot be laid inthe most permanent and substantial manner by the use of stone sleepers,on account of the injury sustained by the rolling stock from therigidity and want of elasticity of the rails. By the interposition of anelastic substance between the sleeper and the rail, this injuriouswearing effect upon the engine would be avoided and the roads might thusbe laid in a more prmanent manner than has heretofore been foundpracticable. In winter also when the ground is frozen the wholesubstructure becomes a solid rigid mass, and it is estimated that therolling stock is deteriorated by this circumstance as much during thethree months of winter as in the other nine months of -the year. Thiswould also be avoided by the use of my improvement, and I thereforepropose to apply it to all rail road chairs whether they rest uponwooden or stone sleepers In the above description my invention is spokenof as particularly applicable to rail road chairs; it is my intentionhowever to apply it to rail road frogs, and to the head and tail blocksof switches; it may also be applied to any form of chair at present inuse.

Vhat I claim is my invention and desire

